QUEENSLAND. BUREAU OF SUGAR EXPERIMENT STATIONS. DIVISION OF ENTOMOLOGY. BULLETIN No. 18. Natural Enemies of Sugar-Cane Beetles | in Queensland. BY J. F. ILLINGWORTH. BRISBANE: | By Authority: Anthony James Cumming, Government Printer. 27-5-21—1,500 Coane, QUEENSLAND. BUREAU OF SUGAR EXPERIMENT STATIONS. DIVISION OF ENTOMOLOGY. BULLETIN No. 13. Natural Enemies of Sugar-Cane Beetles in Queensland. J2F. ILEINGW Orie: BRISBANE: | By Authority: Anthony James Cumming, Governmen t Printer. Bureau of Sugar Experiment Stations, Brisbane, Ist August, 1921. The Under Secretary, Department of Agriculture, Brisbane. Sir,—I have the honour to submit for publication as Bulletin No. 13 of the Division of Entomology, Bureau of Sugar Experiment Stations, a manuscript entitled ‘‘Nataral Enemies of Sugar-cane Beetles in Queensland,’’ by Dr. J. F. Illingworth. I have, &e., Hi. T. EASTERBY, General Superintendent. Approved: E. G. E. Scriven, Under Seeretary. pl 5 FOREWORD. rN WHILE preparing a bulletin on the Australian sugar-cane beetles and their allies, I found that we had so many data: dealing with the natural enemies of these pests, especially after our investigation of the epidemic of fungus at Greenhills during 1920, that I decided it would be best to present these studies in two separate papers. The first of these, ‘A Study of Natural Methods of Control for White Grubs,’’ is in press and will appear as Bulletin No. 12 of our series. The importance of these organisms in the economy of nature can hardly be over-estimated, for, even in the case of our worst pests, natural enemies undoubtedly destroy by far the greater majority ; yet, even with the remainder, those that eseape these foes—probably less than 10 per cent.—man frequently has a keen struggle for supremacy. We can only conjecture what would be his fate without the assistance of these organisms; hence, any effort to become familar with the complex interrelation of our natural allies is time and money well spent. Separated as we are in North Queensland from practically all library facilities, investigation has been carried on under a considerable handicap. Fortunately I brought along my own meagre library, and, with this and the many separates and pamphlets supplied by the Colonial Sugar Refining Company and various other investigators, I have been able to review the literature cited in the bibhography. This information has given me many suggestions, and I am sincerely grateful to all these friends, in various parts of the world, for the invaluable aid that they have given me. IT am also indebted to Mr. E. Jarvis for the assistance that he gave me in the early part of my. investigation, while breeding out the Campsomeris wasps, and for the care with which he has exeeuted the drawings in this paper. And, finally, I am under the deepest of obligations to Mr. A. P. Dodd, since we owe much of our present knowledge of the natural enemies of cane-grubs to the years that he spent here in conscientious work, breeding out the many species of beetles occurring in cane areas. And, furthermere, I would be lacking in gratitude if I did not commend his splendid loyalty and his enthusiastic devotion to his chosen science. P.LatE I.—Showing various stages in the development of the Campsomeris wasps. as they appeared in the trays. Arrows indicate eggs in position. Cocoons of the wasps are to be seen in cells on right. (Reduced; see scale.) Natural Enemies of Sugar-Cane Beetles in Queensland. AN INTRODUCTION. Since Australia appears to be the natural home of Searabeid beetles, this fauna being perhaps the richest in the world, it is not surprising that natural enemies are equally numerous here. While in a few instances we have certain species of these beetles developing in such hordes that they completely devastate crops, the great majority of cur species are seldom conspicuous, since they are undoubtedly held in check by natural enemies. Indeed these natural controlling factors are sO numerous that it is a difficult matter to understand how any destructive cane-beetles can continue to reproduce in such numbers. Undoubtedly man, in his clearing of the forests, has upset the balanee of nature. At any rate there is no question that he has been a most important agent in the depletion of the mative bird life; and these feathered friends are probably the principal factor in limiting the increase of Scarabewid beetles. Moreover, cultivation has had a retarding influence upon many of the parasitic insects, especially the wasps, which normally feed upen nectar; hence the destruction of all the native flowering plants has had a tendency to drive them far into the wilds, leaving the pests to multiply in our fields without these restrictions. However, experiment has shown that we can do much to attract these friendly inseets and retain them in our fields by planting nectar-bearing flowers. Of the many natural agents which combine to hold cane-grubs in check it is a difficult matter to say which is the most important, but, from observations in certain favoured fields during the exceptional seasons of 1920 and 1921, it would appear that none has greater possibilities than the green Muscardine fungus (Jetarrhizium anisoplia Metseh.). In these same fields, too, a bacterial disease (Micrococcus nigrofaciens Northrup) occurred, but it was not nearly so virulent. Though predatory mammals, lizards, frogs, &c., frequently aid materially, birds are undoubtedly our strongest allies. Districts which are regularly visited by the ibises and crows are particularly favoured, for these birds seldom overlook either grubs or beetles. Parasitic and predaceous insects, too, are particularly abundant in Queensland ; of these the digger wasps are probably the most efficient. According to Froggatt (14) about 50 species of Scoliids have been described from Australia, and. about 800 species of Thynnids. 6 NATURAL ENEMIES OF SUGAR-CANE BEETLES. Hence with all these natural enemies, and probably many others that we have not yet learnt to recognise, it is surprising that even a very few of our numerous species of Searabeid beetles should be able to multiply into such devastating hordes. Yet, as Davis has well said (40), when we further reflect that these enemies are likewise attacked by parasites, that some birds and mammals which destroy the beetles may also destroy the beneficial parasites, that the adult of one predaceous larva may prey on the adult of a similar predaceous larva, and that the predaceous larve likewise may attack one another, we begin to realise the immense complexity of the interrelations of these animals. DISEASES.* Funet undoubiedly play a most important part in grub control. especially when chmatic conditions are suitable for their propagation. Fully a decade ago Mr. Tryon (22), in an able address before the Australian Sugar Producers’ Association, stressed the importance of the Museardine fungus (Wetarrhizium anisoplie Metsch.), and urged adequate inquiry as to the methods of multiplying and distributing this useful parasite to combat cane-grubs. And again, in 1914, this same author (25) gave a most comprehensive report upon this fungus, where we read :— ‘“In the field experiment, healthy and Muscardine-infested grubs were intermixed at the bottom of a rectangular excavation, so that they might come in contact one with another, and then covered with scrub soil rich in humus to a depth of 18 inches. By this crude method, based on the observation that the disease-affected grubs oceurred in well-defined areas in the canefields where they were discovered, it was expected that spore-laden soil would be obtainable. “In the laboratory experiment, it having been observed that the spores formed by the Metarrhizium fungus, although very numerous, were also very small, falling into the interstices of the surface of paper when placed upon it; and were with difficulty only moistened, resting in masses On the surface of water, a soil both extremely fine and also unusually rich in organic matter was employed. This had been discovered under peculiar circumstances by the writer, at Bahana Creek, and conveyed some miles to the laboratory for the purpose. In this soil, when dry, it was found practicable to mix the spores, so as to have a relative large quantity of infective material available, and it was noted that it served to originate the disease in cane-grubs confined in vessels containing it—as was found at the expiration of nearly six months, when on revisiting the district the results of a few of the laboratory experiments could still be appraised. It is conceived that it would be quite possible to produce this material in large quantities and distribute it in the drills whilst planting. ‘““As pointed out by me, in my report on the ‘ Grub Pest in the Mackay District ’ in 1896, and in lectures on the subject since, and = Since these diseases have Leen discussed at length in Bulletin No. 12 oily be referred to briefly here. , they will NATURAL ENEMIES OF SUGAR-CANE BEETLES. 7 notably in the one delivered at Nelson, Cairns, in June, 1908, there are grounds for concluding, with but little doubt, that the fungus enemy of Cane Beetle Grubs has, in the past, had considerable influence in locally controlling the numbers and destrictiveness of these marauders of our principal tropical agricultural industry, and that it will continue to do so. It appears within the possibilities, of scientifically devised methods to assist nature by distributing to a larger extent than is spontaneously realised, this destructive agent through which it works.”’ Following upon the peculiar climatic conditions of June and July, 1920, such contagion developed among grubs in certain fields where spores existed in the soil, that the pest was practically wiped out. Moreover, at Greenhills it was not uncommon to find a bacterial disease working in conjunction with the fungus. Indeed so destructive were these diseases that by the end of July it was a difficult matter to locate any living grubs, under such conditions, where shortly before the epidemic had set in there had been a hundred or more per stool. As a natural result, when digging in these fields we could see the grey-green masses of spores that had developed on the dead grubs, and the soil was evidently thoroughly permeated with spores. At any rate, healthy grubs placed in pots of this soil quickly succumbed to the disease, so I decided to recommend the distribution of such soil (48) as widely as possible in other grub-affected areas. It has since occurred to me that this infection could probably be better facilitated by dusting a little of the spore-laden soil over the plants in the planter, for in this way it would be thoroughly distributed throughout the fields. PREDATORY MAMMALS Often have an important bearing in relation to the control of white erubs. Here in Queensland, the bandicoots (Perameles sp.) undoubtedly should head the list. Mr. Tryon (6) (22) (23) also mentions various species of pouched mice (Antechinomys, Sminthopsis, Phascologale ) which have grub-eating proclivities, but I have never had an opportunity to observe them. The flying-foxes (Pteropus sp.), too, though inveterate fruit-destroyers, come in for consideration as destroyers of the adult beetles. Furthermore, on the farm we have valuable allies in the hogs, wherever the crop is to be ploughed out, for these animals are ravenous after the grubs. Some dogs, also, even follow the ploughs to pick them up. Banpicoots.—Though bandicoots are known to be omnivorous feeders, my experience with them in the canefields has been rather favourable than otherwise. While it is a fact that they uncover and cut off many of the cane-roots in their search after grubs, I am convineed that most of their efforts are in the right direction, for they appear to be able to locate the grub by sense of smeil, since they usually dig only in the affected parts of the field. My first definite knowledge as to their insectivorous habits was from the dissection of a specimen, 21st July, 1918, killed during the night in the cane by a dog. Its stomach contained a larva of a cutworm, five caterpillars of unknown species, four locusts, 8 NATURAL ENEMIES OF .SUGAR-CANE BEETUES. one centipede, two large spiders, eight small spiders, two slugs, one small beetle, many small ants, three large ants, eight large crickets, six small erickets, sixteen footless larvee similar to cane-borer, many legs and other parts of ground beetles, and numerous other remains of insects; together with the following bits of plants, which were probably accidentally swallowed: a bit of tree-bark, three small roots, two bits of erass, two small leaves of a weed, and a piece of a dry stick. This certainly suggests an insect diet, and especially at a time of the year when insects were most difficult to find. Specimens examined during March, when the ‘cane-grubs were active near the surface of the soil, indicated a strong preference for this pest, for the stomach was usually well supplied with the chitinous remains of the grubs, with no signs of plant tissue. The teeth of bandicoots are adapted to an insect diet, so they probably turn their attention to potatoes and other garden products when driven to it through a seareity of grubs and other insects. I was interested in this connection to read the remarks of Mr. G. Pott (9), of Proserpine, who stated— ‘‘In Proserpine, bandicoots are very numerous and grubs very searee. You find that where the grubs attack the cane the bandicoots attack the erubs.’’ SAYING Foxes.—Though I have not been able to make any personal observations. upon the insectivorous habits of the flying-foxes, we have the evidence of several careful observers among the growers. Mr. Jodrell (22) notieed the grass under palin-trees at his place at Innisfail covered to a considerable depth with the masticated remains of cane-beetles. He felt certain that these had been killed by the thousands of flying-foxes which frequented the trees during the night. In discussing this matter with Mr. Jodrell since, he told me that the wing-eases of the greyback beetles were easily recognised in the excrement of the bats. Another grower, Mr. R. D. Rex at South Mossman, also made careful observations on the fruit-bats, which congregated in the beetle-feeding trees, even where no fruit was present. He, also, stated that the ground under the trees was strewn with broken parts of the beetles each morning, clearly indicating that the bats had been feeding upon the insects. MoLes AND SHREWs.—I might also mention here that two of the most useful grub-destroyers in other countries are the moles and shrews. From my experience with these animals in the United States, I would say that they ought to be thoroughly beneficial to infested cane areas. Reviewing the literature, I note that the introduction of these friendly agents has been discussed here from time to time, but none of the recommendations have ever been acted upon. Mr. Tryon (6) carefully reviewed the pros and cons with regard to the European mole for the sugar-growers; and Mr. Boyd, editor of the ‘*Queensland Agricultural Journal’’ (10), later went into the matter very thoroughly, urging its introduction for the destruction of grubs; but nothing came of these efforts. =~ NATURAL ENEMIES OF SUGAR-CANE BEETLES. 9 Mr. J. J. Davis (40), in his recent comprehensive paper on the natural enemies of white grubs in the United States, writes in regard to moles and shrews— “The common mole (Scalopus aquaticus) is probably next in importance. Mr. Theo. H. Scheffer, after examining the stomach contents of 200 moles taken in all months of the vear, concludes that white grubs and earthworms constitute the bulk of their food; and Mr. J. A. West finds fram a study of the stomach contents of moles collected under varying conditions in various parts of Illinois, that a good per cent. of the food of moles consists of white grubs and May beetles. ‘“Mr. George G. Ainshe, of the Bureau of Entomology, made some interesting observations on the feeding habits of the common mole in confinement. The mole, which was taken in a field at Nashville, Tenn., June 28, 1911, was fed ten large Phyilophaga grubs, two wireworms, and one webworm in succession, all of which it ate with relish. The mole would eagerly take a grub, quickly crush its head between its teeth, and leisurely eat the remainder of the grub. ‘At Farmington, Mich., October 23, 1914, A. F. Satterthwait saw an abundance of mole tunnels in an old timothy sod badly infested with erubs, the unusual amount of mole work in this field indicating that they, as well as skunks, were attracted there to feed on the grubs. < it Janke Jane) 4: 7 aD 15; male | 45 xs 2 X9 3 X10 4. X11 5 8 7 >. 5 >. 4B} 7 X14 7 ass 8 X16 9 12 ai X17 9 X18 11 14 8 X19 12 X20 e 12 X21 +e 13 X22 14 17 U 39 Mar. 4; female 49 X23 15 X24 ee 16 X25 2. 16 X26 a 18 21 8 X27 ve 19 22, 7 41 11; female 51 X28 it 19 22 7 X29 ag 21 24 | X30 ae: 21 X31 24 a 6 41 14; female 49 H32 a 24. X33 ne OT X34 “al 28 Average Ve avs Weil 39 52 47-8 The second wasp, No. 21, was our most interesting one as to the number of eggs that she produced, after being captured. She lived fifty-one days in confinement, and died on 7th February, after laying sixty-five eggs. Her record is given in full in Table No. 3:— TaBLE No. 3, SHOWING THE EGG REcoRD OF CAMPSOMERIS TASMANIENSIS, WASP INO 21 A SumMeER RBroop. NATURAL ENEMIES OF SUGAR-CANE BEETLES. oO | | { meld BLBECnOM | pee Cem ee Dee ane | eeael Days. | Days Days. Dec. 20 Dees 23. | 8 lao 6 Feb. 4; male | 46 22 oe 7 30 | 4; male | 44 24. Pate | 28 oH | 35 | 8; male 42 30 Jane al gan. 1 3 | 8 4 males) 44: 2, 4 3 Dees 20; female | 48 3 Cin as 4 Th | 5 8 if | 5 7 8 40 23; female | 49 6 9 | 7 10 6 31 16; male 40 7 10 ® 8 9 11 7 36 22; male 44 9 12 3) 12 8 39 27; female | 49 11 13 12 14 12 14 8 13 1) 8 | 13 1D. 8 14 zien 9 35 Mar. 1; female | 46 14 1 ie 6 15 | 15 17 8 39 4; female 48 16 16 18 8 59 25; female | 68 17 20 Ul 38 5; female 47 17 20 7 USE| 20 | TS 20 8 | | 19 20. | 20) 21 23 8 40 11; female 49 21 24. 8 34 6; male | 44 22 25 8 33 6; male | 43 22, 25a 8 38 11; female | 48 23 25 8 34 8; male | 44 24 26 8 | 24 Dey Dil 8 33 8; male 42 25 | 26 : ae 3 17; female 40 26 28 8 38 14; male 47 PAT 29 | 8 35 12; male 44 27 30 | 7 41 18: female 50 28 30 | 9 38 18, female 49 28 30. | 8 | 29 | | PAS) Teale 1 8 36 16: male 46 AX) 2 30 31 2a 1 | Fek. 2 2 | 3 Hey) 7) | 5 7 5 7 8 43 30; female | 53 5 8 | | 6 | | | e | le ETS GUSTeBS | 46-79 30 NATURAL ENEMIES OF SUGAR-CANE BEETLES. It will be noted that both wasps, Nos. X and 21, had an increase of efficiency in the early part of January. During that month Mr. Jarvis was away on his annual leave, so I had to have full charge of this breeding work. I at once began to experiment with these two wasps in particular, to see if I could get them to lay more eggs. From the records I found that each wasp had not averaged an egg a day, so I tried giving them more attention, and removed the grubs as soon as they were parasitized. To do this I tipped them out of the tins very early in the morning, at noon, and late in the evening. On 38rd January I was rewarded by getting two eggs trom No, 21, and on the 5th both wasps laid twiee. Later in the month, it will be noted, this two-ege record was rather constant. Furthermore, on 9th January No. 21 gave me threc egos on paralysed grubs, and she did this again on 5th February. Thus I finally came to the conclusicn that two eggs per day was approximately the best average work of one of these wasps; so made it a practice to examine them early in the morning and late in the afternoon. This practice disturbed the wasps less and they were found to do better under it. Again, it was interesting to note that, when | put more than one erub in the soil with a wasp at the same time, she invariably paralysed them all, though she never laid on more than one. On one oceasion, just to note the result, we placed fifteen third-stage grubs of Lepidiota frenchi with one of the wasps in a large flower-pot of soil, and left them together overnight. The result next morning was most encouraging, for only three grubs remained alive. The wasp had paralysed twelve of the grubs, but only one had an egg upon it. Evidently these wasps consider the grubs their enemies, else why should this individual have paralysed so many more than she could possibly require for her progeny? Undoubtedly, however, this habit would be most beneficial to our crops. if the wasps were more plentiful. AUTUMN AND WINTER Broops. Though we have but little data from actual breeding, field obser- vations cleariy show that these wasps continue their beneficial activities. throughout the year. The temperature of even our coldest winter nights seldom dropping to 40 dee, Fahr. does not seriously inconvenience such hardy parasites, for the adults are always to be found at flowers as soon as the sun warms up a bit in the morning. And, furthermore, we find the larve and cocoons in the soil just as abundantly in winter as at any other season. Yet there is no doubt that both temperature and moisture play luportant parts in the activities of insects; therefore it was not surprising to find in our breeding work that the life-cycle was considerably lengthened as the nights got cooler, or when the cocoons were exposed to drying atmosphere. ILence we may naturally conclude that during the winter, even under natural conditions, their period of development would be materially increased. Summing them up it appears that there are probably at least four distinct broods each year; for convenience we have designated these by the uame cf the four NATURAL ENEMIES OF SUGAR-CANE BEETLES. 51 seasons—spring, summer, autumn, and winter. The first two have been deseribed in detail above, so it is interestine to add here a_ brief tabulation of the available data on the autumn brood. On 4th March, 1919, Mr. Jarvis collected three Campsomeris wasps at flowers, and placed them in separate tins of soil, each supplhed with a grub; these were given the numbers 47, 51, and 79. On 14th March he collected wasp No. 35, and on 19th March No. 22, both at flowers along the Mulgrave River. On this latter date No. 25 was secured from a window in the laboratory. The data on the progeny of these six wasps, though far from compicte, are given in Table No. 4:— TasBLE No. 4, SHOWING PARTIAL DatTA ON AUTUMN BROOD OF Srx CAMPSOMERIS WASPS. Kee No. | Laid. Emerged. | Life Cycle. Sex. | Species. Days. | DW ANE Sie si Mar. 20 May 12 53 Male | C. tasmaniensis Dll ae omen 23 18 56 Female | C. tasmaniensis Shey Al ec ae 16 16) | 61 Female | C. tasmaniensis SO ae 58 17 1 45 | Male ATI yar _: 12 2 51 Male CO. tasmaniensis 51/1 6 5 60 Male CO. tasmaniensis ON vax ae 10 6 57 Female Lay ore ie NZ 14 63 Female 51/7 13 9 57 Male 51/9 15 16 62 Female TRA Vee Sc a 67) 60 Female (C. radula UBIGY os Bie 10 9 | 60 Female 79/4 al 1 | 51 Male Average Ae 5.6 23 56-2 Though, unfortunately, this breeding work was not continued throughout the year, we have made numerous cbservations upon both the winter brood and the parent wasps in the field. During June, 1918, the wasps were particularly abundant in the Cairns district, beine especially seen flying to flowers and close over the surface of the ground in grubby fields. Digging in one of these fields at Hambledon on 20th June, | found the wasp cocoons exceedingly abundant and at the rather shallow depth of about 12 inches. This was accounted for because the soil was very hard and stony just below cultivation, so that it was impossible to dig without a bar. I estimated that about 37-5 per cent. of the grubs in this instance had been eaten by the larve of the wasps. Again, during the winter of 15920, the wasps were observed in great numbers in the fields, both at Meringa and at Greenhills. On 14th July, while investigating the depth of the grubs of Lepidoderma albohirtum in our Meringa plots, cocoons in considerable numbers were turned up at depths of from 12 to 18 inches. I estimated that in this spot 25 per cent. or more cf the grubs had succumbed to the wasps. Digging a pit a cubic yard in size, in another grubby field at Meringa, on the same day, we found the progeny of the wasps even more numerous, and at depths of 12 to 24 inches, the deepest being a young 32 NATURAL ENEMIES OF SUGAR-CANE BEETLES. larva attached to a paralysed living grub in a well-defined cell; this cell was about 1 inch by 2 inches in size, and the grub was lying on its back. The soil in this field was very loamy, so that it was easy for the wasps to go deep. At 9 a.m. many of the wasps, both males and females, were observed here feeding on the flowers of the pink burr. The abundance of nectar-bearing plants in this vicinity had undoubtedly attracted the wasps in considerable numbers, and probably accounted for the high rate (60 per cent.) of parasitism. At Greenhills, 3rd August, 1920, we also found many cocoons of these wasps while excavating; apparently 20 per cent. of the grubs had suecumbed to them. The remarkable delay in the emergence of wasps where the cocoons were exposed to the drying effect of the atmosphere has been recorded by Mr. Dodd (84), and this retarding factor has been noted on numerous occasions subsequently. Hence for the larvee to develop in their normal period they must be kept fairly moist. It is probably for this reason that the mother wasp usually goes so deep into the soil with the paralysed grub before constructing a chamber for the development of her offspring. In one instance, while digging to a depth of 4 feet in the Greenhills soil, I found one of these cocoons in a cell 42 inches from the surface, and many at depths of from 2 to 3 feet. I wish to call attention here to the fact that the number of wasp cocoons turned up by ploughing red voleanie¢ soils is no criterion of the value of these friendly insects in the fields. The abundance of data that we have accumulated during the past four years by digging deep all go to show that most of the paralysed grubs are put lower than the ploughs go. Hence the only way to arrive at the percentage of parasitism would be to excavate under grubby ecane-stools here and there in the fields, to a depth of approximately 4 feet. PARTHENOGENESIS OF CAMPSOMERIS. A specimen of C. radula (wasp O) bred from egg KK of Table No. 1, and presumably unfertilised, lived only twelve days, laying seven eggs. It was further interesting, however, that the only two of these that developed produced a male and a female, thus suggesting that, though the vitality was remarkably shortened, these wasps were able to reproduce both sexes without mating. With a desire for further evidence of this remarkable power of the Campsomeris wasps to reproduce partheno- genetically, a number of separate experiments were started at once. The results of these will be given hereunder, Wasp OO, C. radula, derived from egg HX of Table No. 1, was kept unfertilised, and after an interval of four days she was given a third- stage grub of LZ. frenchi, on which she deposited an egg at once. Though this wasp lived only twenty-seven days, she deposited nineteen eggs on third-stage grubs of L. frenchi. Eight of these came to maturity in the usual time, but only one produced a female wasp. This interesting; record is given in full as Table No. 5:— NATURAL ENEMIES OF SUGAR-CANE BEETLES. oD Taste No. 5, SHOWING THE EGG RrEcoRD OF CAMPSOMERIS RADULA, WASP OO. | Egg No. Laid. Hatched, | Mae oe | lee | Mee GE Wecoe Gu ee LBS ea A | es Days. Days. Days. OXO VAL Soli) Sea Janeel2 a a bKeb: "215 male) 11) 843 OGI2" «2: 10 1 a Ce Soma | 22; male 43 OO/3 1) 14 7 33 23; male 43 OO/4 13 16 7 00/5 13 16 7 | OO/G 15 18 a 32 | 26; male 42 OO pine i 16 19 6 31 25; male 40 OO/8 5. 17 | OO/9r 1. iy 20 7 OO/10 .. 18 OOM. 20 23 7 32 Mar. 3; male 42 OO/12 .- 22 OOS. 22 25 OO/14 ..| 2: OOS. =: 24 2H 7 32 7; male 42 OO/1G6.-.: 25 OOVAT 9... 28 30 7 40 19: female 5O WOVAS 28 OOJ9STS= |. Hebs 1 Feb. 4 Average | de 6-9 35-28 | +4 43-125 ‘Wasp OOO, C. radula, derived from egg QX of Table No. 1, was carefully exeluded from all possibility of mating. She lved thirty-two days and also produced nineteen eggs; of these only ten developed, and all were males. ‘““Wasp K, C. tasmaniensis, derived from egg X27 of Table No. 2, though not allowed to copulate, was much more prolific. She lived sixty- two days, laying eighty-four eggs, and finally came to an untimely end, being cut to pieces by a grub. Forty-five cocoons were obtained, from which emerged thirty-seven males and one female; the seven remaining cocoons failed to emerge, and the pup in them were found to be rotted.”’ Most remarkable for the number of eggs produced by an unfertilised female was wasp Q, hatched from the thirty-eighth egg laid by wasp No. 21. This wasp emerged on 11th March, 1918, and began laying at onee, which she kept up until 20th May, depositing ninety-five eggs. The next day she was found dead, and had lost ten segments of one antenna, a segment of one intermediate tarsus, and two segments of the other, while both of the posterior tarsi were considerably mutilated. These ninety-five eges produced sixty-eight cocoons, from which issued forty-two wasps, all males; the remaining cocoons contained rotting pup. In most of our other experiments along this line the eggs all developed into males. Finally, however, we took the lone female that developed from egg OO/17 of the unfertilised wasp OO on 19th February ; this wasp also was not permitted to meet a male, but she laid upon a grub the day after emerging, and, though she met an untimely death at the hands of a grub that she was attempting to sting on 29th February, she had already laid seventeen eggs. Several of these eggs, C 34 NATURAL ENEMIES OF SUGAR-CANE BEETLES. however, failed to hatch, but turned brown and dried, as though lacking fertility. Four of the larve spun cocoons, but the only wasp that was obtained from these was a male. Hence it would appear that the vitality is largely spent in the second generation, without mating. Yet it is remarkable that they are able to reproduce both males and females at all without mating, even in the first instance. FurtTHer BIOLOGICAL OBSERVATIONS. “The Egg of Campsomeris radula measures 3-20 mm. by -90mm.; colour greyish white, elongate-cylindrical, with longitudinal axis slightly curved, and rounded ends, that attached to the grub being less obtuse than the other. Occasionally eggs are not regularly cylindrical through- out their leneth, but may bulge shghtly near the centre.’ “Tt was found that the eggs were not always placed in the normal position, on the third abdominal segment of the venter of the grub, but sometimes nearer to the thorax, or not on the central line.’ ‘* A wasp, tipped suddenly out of its cage, was seen to be clinging to its host, and in the act of laying an egg, which projected about three- quarters of its leneth from the ovipositor. The inseet remained clinging te the grub, and finished ovipositing in the broad daylight, gluing the ego as usual to the ventral surface.’”’ “The eges were easily detached and transferred to other grubs. Four eggs laid on 12th March, 1918, were detached and placed on a single erub, where they hatched and developed into maggots, that ultimately spun abnormally small cocoons. A male wasp emerged from one of these on 7th May, and a male and female four days later.’’ In our experimental work the eggs were frequently subjected to destroying agencies. ‘‘Fully 20 per cent. of the eggs obtained from a cage of females of C. tasmanicnsis during December were destroyed by a species of Acarus, that very often occurs as a predaceous enemy on the bodies of soil-frequenting white grubs. In another instance 40 per cent. of the eggs laid during January were destroyed by Acari.’’ ‘* Koos, too, were often found to be diseased and to turn brown and dry up. They also became marked with short brown streaks near the attached end, in which case they ultimately rotted away and became discoloured with brown shades as though destroyed by bacteria.” The Larve were also subject to attacks of a fungus, especially when very young, and sometimes they became entirely covered by a white fluffy growth. ‘“In the event of a host dying before the maggot has attaimed advanced growth, the latter, if a couple of days old, may be successfully transferred to another paralysed grub, and will again pierce its skin and resume feeding. If, however, the parasite be half grown it will be necessary when transferring to make an incision in the skin of the host, and place the head of the maggot against the hole; when it will sometimes resume feeding, but not infrequently fail to become attached and consequently perish.”’ NATURAL ENEMIES OF SUGAR-CANE BEETLES. Se) C1 The larve, just prior to spinning their cocoons, eject water at intervals from the end of the body, whenever disturbed, squirting it to a distance of 6 inches or more. I ean offer no explanation for this peculiar habit. “On 15th January, 1918, a maggot of C. tasmaniensis that had been unable to complete the upper surface of 1ts cocoon, because the cell lacked a roof, as noted above, was placed on its mat of silk in a special cell to watch the transformation to the pupal condition. Six days later, exudation of moisture had taken place, and it had shrunken noticeably, the segmentation being very angular and conspicuous. Next day the maggot had shrunken to 19 mm. in length, the skin having lost its glossy appearance, and viewed with a lens the entire surface was seen to be closely wrinkled. The head-end had contracted and lost the power of vigorous motion, the segmentation showing as angular ridges. Pupation took place on 26th January (eleven days after spinning).”’ “The Adult Males, just after emerging, have a habit of remaining in - the vicinity of their empty cocoons, as being, presumably, the most likely spot for the appearance of the females. Males that emerged from cocoons at the insectary were at once thrown out of the door, but after flying for a time close at hand they invariably tried to get back to the breeding cages, and if the door happened to be closed they flew round to the window and were observed trying to get into the room.’”’ ‘* Wethod of Paralysing Grub.—On 4th February a pot of soil (elay- loam) 1 foot in depth was prepared, and a specimen of C. radula was placed on top of the soil with a stage III grub of LZ. frenchi lying close to it. During the next ten minutes the wasp paralysed four grubs of L. frenchi, its mode of attack being to seize them by one mandible and at once sting them on the ventral surface, Just anteriorly of the front cox. After a few seconds the sting is withdrawn and immediately thrust into the throat just in front of the maxille, the whole operation lasting less than a minute, the sting being kept moving shghtly as though probing the wounds and administering successive injections of the poison. The fourth grub was paralysed at 2.55 p.m. and by 3 o’clock had been under- mined and half-buried by the industrious wasp, which came two or three times to the surface bringing with it pieces of soil, when it crawled over the uncovered portion of the grub’s body as if to gauge its dimensions, and then again disappeared below the soil, which was heaped loosely around the half-buried grub. No further motion was noticed for three minutes, and then the body was suddenly pulled vigerously downwards, leaving only the three last segments exposed to view; the wasp having apparently been busy in the soil, excavating a tunnel for the reception of its victim. No further movement was apparent for six minutes, when the body was again pulled downwards, leaving the anal segment just visible among the loose earth and level with the surface. By 3.12 p.m. another pull down, and the grub had disappeared from view (seventeen minutes after being paralysed). When examined next day at 9 a.m. the wasp was on the surface, and the grub was found 10 inches below ground level, and 24 inches out of the perpendicular; thus it had 36 NATURAL ENEMIES OF SUGAR-CANE BEETLES. been transported from the surface in a vertical direction at an angle of about 80 degrees. The grub was lying with its venter in a horizontal position, and an egg had been laid in the normal situation. ‘On 5th February a wasp was placed on the surface of the same pot of soil used in the above experiment, at 9.30 a.m., a grub of DL. frencha being placed with it. The insect stung the grub in the same manner, and whilst so engaged allowed me to pick up the grub and examine the mode of attack through a pocket lens in a strong light. The wasp had hold of one mandible ot the grub near its base, in such manner that the latter could not properly close its jaws or bite in a forcible manner. After the sting, however, the free mandible of the victim seemed powerless te move, and no attempt was made to bite. The grub was stung at 9.30 a.m. and thirteen minutes later the anal segment alone was visible at ground level, the wasp then coming to the surface and at once burrowing below again. By seventeen minutes from the time of stinging the grub had been buried out of sight. When examined next day, at 9.80 a.m., the erub was found 44 inches below the soil, and 2 imches out of the perpendicular; it was lving at an angle, venter uppermost, among the soil, and no egg’ was present. ‘On 6th February another specimen of C. radula was placed on the surface of the soil with a cane-grub (L. frenchi) and whilst engaged in stinging was examined under a strong light. It was plainly seen that when stinging the second time the sting was thrust into the throat just in front of the maxille and moved about in a probing manner but not withdrawn, the reason inferred for such an action being the greater facility afforded for injecting a quantity of the paralysing fluid. The first sting is administered between the head and the anterior coxe. When examined next day at 11 a.m. the grub was found at a depth of 54 inches, while the angle of the line of transportation was about 1s degrees. It was lying on its back, venter uppermost, but not in a cell, and an egg was attached in a normal position. Two holes were noticed on the surface from which the wasp had emerged, one where the grub had been lying when stung, and the other 3 inches from it.’’ On one occasion I placed a wasp, C. tasmanicnsis, In a large glass jar with moist soil to a depth of 6 inches, and supplied her with a large third-stage grub of Lepidoderma albohirtum, which I dropped in on the surface of the soil beside her. She at once became alert and moved around to the back of the grub as it lay on its side. The wasp then waited until the grub raised its head, when she sprang on the side of its body and seized it by the nearest mandible. This hold being secured, the grub appeared powerless to close its jaws, and she proceeded to sting it as noted above. Doubtless the wasps under natural conditions sometimes fail to get such a death-grip, and they themselves are then bitten and torn to pieces, as has been observed during our breeding work, and noted above. A few hours later I found the wasp with the grub at the bottom of the jar, working away industriously. Since she was at one edge and unable to go deeper, she proceeded to travel around and around in plain NATURAL ENEMIES OF SUGAR-CANE BEETLES. Oo =~ View, so that I was able to observe her activities. She first dug ahead of the grub, pushing the soil back around it until she had no more room to dump the soil; then she seized the grub and pulled it forward into the new eavity, when she continued in the same methodical order to excavate in front of the grub again. She travelled twice around the jar while I watched her, during several hours, so I gave up the idea of waiting for her to lay an egg upon the host. Next morning, however, the grub was in an oval cell at the edge, and lying on its back, so that I could clearly see an ege placed in the normal position on its venter. It would appear that it is the instinct of these wasps to go as deep as possible, as we have observed in the field; but it certainly looks as though they waste a lot of valuable time; yet they probably know best. Since the hyperparasites are rather abundant in cocoons placed near the surface, by going deep they probably better avoid these enemies, as well as secure more even conditions as to moisture, temperature, &e, It appeared to be rather a delicate problem for the wasp to sting the grub just the right amount. If she gave it too much venom the host died too soon, sometimes even before her egg hatched; and on the other hand, if she gave it too little the grub revived, and the loosely attached egg was soon knocked off. In our work we experienced considerable difficulty with both of these extremes, Since, as we found, it took about three days for the larva to hatch and approximately eight days to feed, the following tabulation indicates on an average the difficulties that we had to contend with on account of the grubs dying too soon. DURATION OF LIFE OF GRUBS PARALYSED BY CAMPSOMERIS. | Average Days Date Stung. Date Died. Lived. | Daves. Jan. 6 ae Jan. 21 15 6 Oe. | 19 8 12 4 13 ae 15 2 14 ae DNS) 11 16 oe 20 4 17 te Hebaeao 7 21 a Jan. 29 5 21 kA 28 7 Dee ee 31 9 Die Hc 26 3 25) Ae Fek. 1 a 30 se 1 2 31 =e 5 8 Average .. Rar 8:3 Hosts.—Since these wasps reproduce continualiy throughout the year, they must necessarily adapt themselves to a variety of hosts. Their main prey, Lepidoderma albohirtum, being only available during the first half of the year, they continue by using any of the closely related grubs, especially those having a two-year life-cycle. Mr. Dodd (34) records the above host, and three others—Lepidiota rothei, L. caudata, and 38 NATURAL ENEMIES OF SUGAR-CANE BEETLES. Anoplognathus boisduvali—and during cur extensive breeding, 1917-18, we added Lepidiota frenchi to this list. It was interesting to observe, at that time, that the Cainpsomeris wasps took no notice of the large third-stage grubs of Dasygnathus australis, not even paralysing them. Tue IMporTANCE OF NECTAR-BEARING PLANTS FOR SCOLIIDS. It is well known that the adults of these parasites subsist upon sweet secretions, which they secure largely from flowers, when they are to be had; they also feed upon honeydew, and in breeding them in captivity we found that they take any form of hquid-sweet that is offered them. As far back as 1901, Mr. J. C. Clarke (11), of the Hambledon Sugar- mill, Cairns, called attention to the importance of planting Congo or pigeon pea (Cajanus indicus) around each field, and the growing of the Bona Vista bean (Dolichos lablab) as a crop for green manure, so as to encourage the multiplication of parasitic insects which feed on the nectar. Ile observed that the parasitic wasps were abundant at the flowers; and at the time of harvesting the cane, close by in the same field, he discovered many of the larve of these parasites in the soil where they were destroying the cane-grubs. In Mauritius, too, the interesting observation was made that Tiphia parallela, which was introduced from Barbados, only reproduced suecess- fully in localities where nectar-bearing flowers were present (33). In its native home this species never was known to visit flowers, for it fed upon the honeydew from aphids. In Mauritius, however, plant hee are so well controlled by natural enemies that the wasps were compelled to turn their attention to flowers for existence. These observations would suggest that our own native parasites of the white grub might be considerably assisted and encouraged if we provided them with suitable nectar-bearing flowers in the vicinity of the infested cane areas. Naturally these wasps in their quest for food are led far into the wild country, and, sinee they can find their natural prey (white grubs) there under the grass-roots, they seldom return to the cane areas to oviposit. At any rate this suggestion is borne out by observations in every district where we know the wasps to occur. Along the banks of the Mulgrave River these wasps, of various species, are commonly found on almost any sunny morning feeding on the blossoms of Crotalaria and other weeds. Also, in the grubby districts near the South Johnstone Central Mill, | have frequently seen the female Campsomeris wasps in abundance feeding on the flowers of the pink burr, and whatever suitable cultivated flowers were available. The Klondyke cosmos, or daisy, an orange-coloured tlower, appeared to be particularly attractive to the wasps. Then, too, at Babinda, where the native scrub borders the new cane areas, it is not uncommon to see these wasps feeding on the flowers of wild raspberry and other native plants. Undoubtedly this feature of the problem is worthy of considerable further study. NATURAL ENEMIES OF SUGAR-CANE BEETLES. 39 Notes ON OTHER SPECIES. We have not been able to investigate the life-history of the several other seoliids, but no doubt it is very similar to that given above. Discolia soror Smith, our next plentiful species in cane areas, appears to prefer sandy-loam fields along the river flats. Here they feed on the flowers of Hugenia and other plants; they are also particularly fond of the honeydew on the leaves of corn infested with leafhoppers. In fact in this latter situation one can collect most of our Seoliid and Thynnid wasps. Mr. Dodd has reared specimens from cococns collected while ploughing, and the wasps emerged on the following dates:—29th June, 27th August, 11th and 25th November, and 3rd December. Scolia (Diclis) formosa Guerin apparently favours the areas bordered by native scrub; at least all of our specimens have been taken in such localities by Mr. Dodd. He found them at Kuranda feeding on flowers of Duranta, at Babinda on the flowers of pumpkin and an unknown creeper in company with Campsomeris tasmanicnsis, and at Greenhills on the flowers of Evodia. Campsomeris (Trielis) ferruginea Fabr. also apparently favours the borders of scrub. Our specimens were taken by Mr. Dodd at Greenhills in January on the flowers of Tristania and Evodia, and at Kuranda in April on flowers of an unknown scrub tree. Campsomeris carinifrons Tarner appears to be rather rare in the Cairns district. I have seen the males feeding at the flowers of the pink burr at Greenhills. A female captured by Mr. Dodd at our station on the flowers of the pigeon pea, in June 1920, refused to take any notice of stage IIT grubs of Anoplognathus and Anomala kept in the soil with it for several days. Liacos insularis Smith is also found near serub. The few specimens observed by Mr. Dodd were captured on dead wood in the scrub. He tried to get a female to parasitize third-stage grubs of L. albohirtum, Anoplognathus, and Anomala; these were kept a week im soil with the wasp without result. In June, 1920, Mr. Dodd also took a female in the early morning asleep on tchage at Babinda. Tiphia intrudens var. brevior Turner is rather common in the Cairns district. Specimens were frequently seen around cornfields at Meringa feeding on honeydew. HYPERPARASITES OF THE ScouupD Wasps. That such abundant parasites should themselves be parasitized is a foregone conclusion. For many years it has been known that they were preyed upon by various species of Bombylid flies and Rhipiphorid beetles, in countries where the life-histories of searabeid grubs have been carefully studied. Hence it was not surprising that Mr. Dodd (34) discovered these same parasitic enemies of the wasps here—the natural 40 NATURAL ENEMIES OF SUGAR-CANE BEETLES. home of lamellicorn beetles—during the stage in the investigation when many thousands of the eane-grubs were being collected. In this breeding work he established definitely the relation of Hyperalonia funesta Walker, and Emenadia cucullata Macleay, to our common scolid parasites, H, funesta is very common in the cane areas about Gordonvale, and is seen everywhere in grass paddocks, even far removed from canefields. These flies have a characteristic habit of hovering low over the ground, the wings vibrating so rapidly that only the body ean be seen, and it appears to be motionless in the air. Again, they are frequently seen on the ground, where they appear to be intently examining the surface of the soil. Mr. Davis (40) remarked that since the flies are incapable or entering the soil, and in view of the further fact that they frequent flowers and feed on honeydew produeed by aphids at the same time that the seoliids are active, it is conceivable that the flies oviposit on the flowers or possibly directly on the wasps and that their eggs are carried away by the host and deposited with its own on the white grubs. Mr. Dodd observed that the larva pupates within the host eocoon ; and he took pupe from these cocoens in October. The pup, as shown in the drawing, is a curious-looking creature with projecting spines from the head and tail. The abdomen is rather cylindrical with peculiar comb-like rows of curved spines topping the ridges on the dorsal surface, undoubtedly used to support the body and to aid the inseet in its movements when emerging. Emenadia cucullata, our most common Rhipiphorid beetle, is frequently met with in considerable numbers resting on the leaves of fig along roadsides and bordering cane areas. Mr. Dodd (34) bred this. species from scolid cocoons. Apparently nothing is definitely known ot the habits of the adult beetles and the way in which they parasitize- the wasps. Ma. Davis (40) hazards the suggestion that the ege is. probably laid on or near flowers frequented by the wasps, or possibly upon the host itself, and that the egg or the recently hatched Rhipiphorid larva becomes attached to the wasp and is in due course deposited on a white grub at the same time that the wasp deposits her own egg. It would be interesting to know what percentage of the scoliids are destroyed by these parasitic enemies, but unfortunately this is a phase of the problem on which we have no data. Yet, when we consider the comparative abundance of wasps that are known to prey upon grubs in our cane areas, we are forced to conclude that a very large majority of them must suecumb to natural causes. Otherwise, with their prolific reproduction they would be able to hold our eane-beetles in cheek with no other assistance. Thynnide. These wasps are included here because they probably have an important bearing upon the erub-pest, though as yet there is little definite data. However, the suggestion by Froggatt (14) that they probably lay their eggs upon Jamellicorn larve has recently been demonstrated by Dr. Williams (46). The former author gives the following interesting summary of this family :— ‘“These handsome flower-wasps are closely allied to the members of the previous family, as they have similar wingless females of such peculiar shapes that, if examined alone, they would never be taken for the consorts of the large wasp-like Thynnus, with its lone stout antenne, well developed legs, and large powerful wings. The males fly about the flowers of Leptospermum and euecalypts, and when captured bite and pretend to sting by turning up the tip of the abdomen, which ends in a horny, harmless process. Fortunately, when hunted for in summer, most of our commoner species can be taken in copula with the smaller female, with which he flies about quite easily; when caught the female immediately detaches herself and falls to the ground, where she crawls out of sight, so that care must be taken by the collector to keep each pair captured in a box by themselves, or else when once mixed up it is impossible to determine unknown species. Australia is the headquarters of this group, for, of about 400 deseribed species, 300 are peculiar to this country; the others are chiefly confined to Brazil and Chili in South America, with a few from Asia and the Islands. Smith has described a ereat number in the British Museum catalogues; Westwood, others; and Guerin, those collected during the Voyage de Coquille in 1830; but as many of these were determined from single specimens of one sex, it Is certain that, when a collection of sexed specimens ean be compared with the types, the number of species will suffer considerable reduction. ‘‘Nothing definite is known about the earlier stages of their develop- ment; I have, however, obtained cocoons composed of a stout silken case enveloped in a thin outer second papery covering, oval in form, with a nipple-like projection at the extremity, from which I have bred one of our large species. These cocoons are buried several inches in the ground like those of the Scolias, so that the females, whieh are furnished with short, stout, spiny legs well adapted for digging, probably lay their eggs in lamellicorn larvie living in the loose soil.”’ Several species of this family are abundant in the Cairns district, the most common ones collected in the vicinity of cornfields, where honeydew is available, being Zaspilothynnus vernalis Turner, Thynnus pulchralis Smith, Epactiothynnus bipartitus Turner, and E. opaciventris Turner. The males of the first two species are beautiful, large. wasps; their wingless mates, living in the soil, probably paralyse grubs in a manner similar to that already described. Dr. Williams (46), while in Australia in 1919, experimented with our commonest small species, Epactiothynnus opaciventris, and found that the little wingless female was very effective in paralysing lamellicorn erubs. Conditions, however, did not appear to suit the wasp, so only one egg was deposited. It was placed on the mid-ventral line; thus in appearance their work is very similar to that of the Scoliids. Concluding this short paper Williams remarked upon our immense Thynnid 42 NATURAL ENEMIES OF SUGAR-CANE BHETLES. population of several hundred species, far outnumbering the Scoliide, and thought that it might be affirmed with some degree of certitude that, like the latter, they preyed essentially on lamellicorn beetle grubs. Dexiide. Mr. Dodd reared eight species of these beautiful flies from cane- erubs, during his investigations of many thousands of this pest, and came to the conclusion that the percentage of grubs destroyed by them was decimal (34). In recent years, however, we have done scarcely any of this work behind the ploughs, so have httle new material to present, except as to the occurrence of the adults. Though these flies are usually more common in scrub areas, the following species are frequently rather abundant in the fields about Gordonvale :—Rutilia inornata G. & M., R. splendida Don., R. pellucens Maeq., and Amenia imperialis Rob. Desy. The first is the dull species with bluish reflections, designated by Mr. Dodd as D. No. 4. He bred it from grubs of Dasygnathus and Anoplognathus. The second, a bright blue-green species, is frequently seen on the trunks of trees and on posts adjoining canefields. Mr. Dodd reared it from Dasygnathus grubs, and designated it as D. No, 23. The third, a dull species with greenish reflections, was reared by Mr. Dodd from the grubs of Lepidiota rothet. The fourth is a brilliant green species with a bright-yellow face. Though we have no data as to its relation to the grubs of sugar-cane, its abundance in certain grubby fields would suggest that it was there for that purpose. I caught dozens of these showy flies at the edge of our experimental plots at Meringa, during the 1918 season, when grubs were there in such numbers that they did considerable damage to the crop. We placed the flies in cages over soil containing grubs, but failed to get any noticeable result. Dissection of the females, however, showed that they still retained a few maggots of rather large size; and in one instance a maggot about 2 inch in length was dropped by a fly that I was holding rather tightly. It is generally supposed that these fhes drop their maggots into cracks, &¢., in soil which is infested with grubs, hence retaining the larve for a considerable period would enable them to develop strength, so that they would be better able to successfully locate their hosts. Another beautiful heht-green species has been commonly observed at Greenhills, especially by Mr. Dodd during the last two seasons, 1920 and 1921. In his earlier notes (34) he designated this unnamed species D. No. 33, when he bred it from Anomala and Horonotus grubs. The adults are frequently observed during the day sitting on cane-leaves and on posts in locations where grubs of the above hosts were plentiful in the soil. NATURAL ENEMIES OF SUGAR-CANE BEETLES. 43 Tachinide. Two species of this family have been repeatedly reared from beetles taken in the field. The small brown dipteron with a dark head, which Mr. Dodd (354) designated as D. 6, is by far the most common. This insect was first bred out in 1914; and though numbers of the flies have developed every season from beetles collected in the field, we have been unable to get the species determined. Whilst these flies are only about is ich in length, their progeny appear to be rather numerous, for we find from six to a dozen in a single beetle. They apparently favour the ereyback beetles, Lepidoderma albohirtum, since these insects are exposed on the feeding-trees both during day and night; yet during the past season (1921) I bred them from several Lepidiota frenchi, a species which hides in the soil Quring the day. The large Tachinid, a specimen of which was first bred by Mr. Jarvis (85) during January, 1917, is also fairly common-in the region about Gordonvale. During the past season | have secured puparia of this fly from both of the above species of beetles. I have invariably found a single larva in each beetle, just as Mr. Jarvis did, so he was probably incorrect in assuming that this parasite normally lays two or more eggs on a single beetle. The fly is a very conspicuous species, and yet we have been unable to get it determined. Large specimens are fully $ inch in length; the head and upper part of thorax are bright golden, the latter marked with two black longitudinal stripes on either side of the median line, the inner stripes shorter; the forward portion of the scutellum is also blackish; the abdomen is black, marked by three broad erey cross-bands. This species is found in the foliage of trees in which the beetles feed, and is usually more common near serub. 44 (4) (7) (8) (9) (10) (11) 1892. 1893. 1894. 1895. 1895. 1896, 1896. 1898. 1899, 1902. 1902. 1902. NATURAL ENEMIES OF SUGAR-CANE BEETLES. ANNOTATED BIBLIOGRAFHY. TURNER, R. E.—Insect Pests (Lepidoderma albo-hirta). Sugar Journ. & Trop, Cult. i, Oct. Supplement, p. 5. Life-history and control measures. Sce also editorial, p. 182. Tryon, H.—Insects as Fungus Hosts, Trans. Nat. Hist. Soe. Qld. 1, 51-59. A general review of the relation of fungi to insects. CoLONIAL SuGAR REFINING Co.—Grubs and Insect Pests (orig. rept. pub. 1893). Sugar Journ. & Trop. Cult. iii, 103, 124. Notes on parasitic fungus imported from France to Home- bush and Goondi; results not promising Also notes on other fungi, fowls as predators, &e. Ouuirr, A. §.—Australian Entomophytes or Entomogenous Fungi, and. some account of their Insect Hosts. Agr. Gaz, N.S.W. vi, 402-414, four plates. An historical account of these fungi, together with descrip- tions of the various species studied. WaLuer, 8. S.—The Grub Pest. Sugar Journ. & Trop. Cult, iv, 115. Advocates protection of native birds. Tryon, H.—Grub Pests of Sugar-cane. Dept. Agr, Brisbane, July, 1895; pub. 1896. Among many other phases of the subject, discusses natural enemies. Tryon, H.—Grubs. Sugar Journ. & Trop. Cult. v, 145. A reprint of some of the factors of control as outlined in his bulletin on the grub-pest of sugar-cane. ‘*Scrutator.’’—The Grub Pest (Lepidiota squamulata). Sugar Journ. & Trop. Cult. vii, 146. In an orchard on Pioneer River a persimmon tree had many dead beetles under it for past two years. The leaves were much eaten, and the ground was white with the corpses of the beetles. Beetles confined after feeding on this tree soon died, while some from a fig lived for a considerable period. See also editorial, p. 244. Porr, G—Cane Grubs. (Agr. Conf. Mackay.) Qld. Agr. Journ. v, 136. In the Proserpine district, bandicoots were plentiful and grubs scarce. They go after the grubs. The birds also destroy an enormous quantity of grubs and should be protected. Much of the trouble probably was due to the destruction of birds by kanakas. Boyp, A. J.—Extermination of the Cane Grub. Qld. Agr. Journ. x, 468. An excellent description of the mole, -Talpa europea (?); urging its introduction for the destruction of the grubs. See also xix, 328. Frogeatr, W. W.—A Natural Enemy of the Sugar-cane Beetle in Queensland. Agr. Gaz. N.S.W. xiii, 63. Gives an account of Mr. J. C. Clarke’s observations at Hambledon Mill, dealing with wasp parasites of cane-beetles. Also advocating certain flowering plants to attract the wasps. TRYON, H.—A Parasite of Sugar-cane Beetle Grubs. Sugar Journ. & Trop: Cult. x7) die Life-history and habits of a wasp, Dielis formosa Guerin. Also published in Qld. Agr, Journ. x, 133. (13) (14) (20) (22) (23) ) AN bo Hr 1904, 1907. 1909, 1969. 1909. 1909. 1909. 1910. ial It Mate 1914. NATURAL ENEMIES OF SUGAR-CANE BEETLES. 45 CoLONIAL SuGaArR ReEKmNrinG Co.—Notes on the Means of Checking the Grub Pest. Printed Cireular, Ist Nov. 1904. No apparent results were gotten from the sowing of fungus. Froccatr, W. W.—Australian Insects. William Brooks & Co., Ltd., publishers, 17 Castlereagh St., Sydney. Thynnide (p. 100): about 300 species described; ‘‘young probably reared on lamellicorn larvee.’’ Scoliide (p. 102): ‘*about 50 species have been described from Australia. ’’ ‘Elateride (p. 166): Aust. to Qld.’ Asilidee (p. 298) : ‘‘Craspedia coriaria destroys cane beetles.’ Tachinidw (p. 312): ‘Australian species not worked up.’’ Dexiide (p. 313): ‘‘ Parasitic on lamellicorn grubs. ’’ COLONIAL SuGAR REFINING Co.—Grubs. Ann. Rept. 1909, p. 43-52. Experiments with young sorghum or imphi at Goondi to kill erubs gave no apparent results. Gipson, ALFRED.—Fowls and the Grub Pest. Aust. Sugar Journ. i, 184. An extensive experiment, using travelling fowl-houses, &e. Lucas, A. H. S., & Le Sover, W. H. D.—Thé Animals of Australia. The fruit-bats (Pteropodide), p. 36. Pouched mice (:lite- chinomys, Sminthopsis, Phascologale), p. 119-125. Bandicoots (Peramelidew), p. 133. Lizards (Varanidide), p. 256; (Liliqua), p- 246. Frogs (Amphibia), p. 259. Tryon. H.—A Cane-grub Parasite. Aust. Sugar Journ. i, 79. The mites infesting the grubs were not held responsible for their death, Lynwood Estate, Isis district. “‘Agrypnus mastersi ranges from W. b) YounG Bros., Messrs.—A Cane-grub Parasite. Aust. Sugar Journ. i, 29. A mite attacking grubs. Tryon, H.—The Cane-grub Pest. Aust. Sugar Journ. ii, 409. Discusses preservation of natural enemies, and introduction of others, stating that he knows of no insect enemies of the cane- beetles outside of Queensland that he could commend for introduction. The introduced ant (Pheidole megacephala) is not considered an important enemy of the cane-grub. MaucHan, J. C.—Natural Enemies of the Cane Grub. Journ. ii, 161. Brown lizard eating grubs; the holes that they excavate are very similar to the work cf bandicoots. Aust. Sugar Tryon, H.—Grub Pest of Sugar-cane, Lepidiota albohirta; a neglected aspect. Aust. Sugar Journ. ii, 532. A discussion of natural enemies. 1, predatory mammals; 2, predatory birds; 3, predatory insects; 4, parasitic insects; and 5, plant parasites (fungi and bacteria). Fungus prolifie at Goondi in 1895. Fungus cultures from France had previously been sown in that locality. No subsequent trouble from grubs there. Suggests application of fungus to other fields. Mr. Jodrell referred to flying-fexes killing beetles; and also his experience with the fungus. Tryon, H.—Natural Enemies of the Cane Grub. ili, 62. Discussion of bandicoot and pouched mice as grub-destroyers. Aust. Sugar Journ. Cane Grub Destruction. Aust. Sugar Journ. vi, 582. Discusses parasitic control, with remarks on hyperparasites, parasitic fungi, &e. The Samoan fungus liberated in fields around Gordonyale. JARVIS, E. (37) 1914. 1915, 1915. LOLS: 1915. 1916. 1916. 1916. Oasis USN ( Ge 1918. NATURAL ENEMIES OF SUGAR-CANE BEETLES. Tryon, H.—Cane Grub and Muscardine Fungus. Aust. Sugar Journ. vi, 631, Green Muscardine fungus from Samoa said to already occur in the Cairns district; named Metarrhizium anisoplie (Metschinoff) Sorokin. This fungus found in 1901 on My, Blackwell’s farm, also at Highleigh. This article summarises. information on this important subject. Jarvis, E.—Combating Insect Pests. Aust. Sugar Journ. vi, $03. Notes on experimental work with Samoan fungus. Jarvis, E—Combating Insect Pests. Aust. Sugar Journ. vii, 140. Discusses natural control: fungus, mammals, birds, and insect enemies, &c. Jarvis, E.—Combating Insect Pests. Aust. Sugar Journ. vil, 301. Preliminary notes on the habits of the interesting Elaterid beetle larva, which Mr. Dodd kept under observation for a period of almost two years. Mr. Dodd’s complete notes on this specimen are given above. Jarvis, E— Combating Insect Pests. Aust. Sugar Journ. vil, 5 Notes on predaceous and parasitic enemies of cane-grubs, and hyperparasites. Jarvis, E.—Combating Insect Pests. Aust. Sugar Journ. viii, 218. Notes on occurrence of Muscardine fungus at Meringa. Jarvis, I.—Combating Insect Pests. Aust. Sugar Journ. vill, 679. Notes on centipede destroying cane-grubs. JARVIS, E.—Notes on Insects Damaging Sugar-cane in Queensland. Qld. Bur. Sugar Exp. Sta. Div. Ent. Bull. No. 3. A list given of the natural insect enemies of cane-grubs, p. 35. CuarMoy, D. p’E. DE.—Report on the Importation of Scoliid Wasps from Madagascar. Dept. Agr. Mauritius, Dec. 1917. Calls attention to the importance of nectar-bearing plants for success with these wasps. Dopp, A. P.—The Cane Grubs of Austrasa, part ii. Qld. Bur. Sugar Hxp. Sta. Div. Ent. Bull. No. 6. A continuation of the studies begun in Bull. No. 2, with notes. on natural enemies, hyperparasites, &e. JARVIS, E.—Combating Insect Pests. Aust. Sugar Journ. ix, 121. Notes on dipterous parasites of cane-beetles; also refers to common parasites of the grubs. Muir, F.—The Introduction of Scolia manile Ashm. into the Hawaiian Islands. Ann. Ent. Soe. Am. x, 207. This parasite was introduced to combat Anomala orientalis Waterhouse, which was first recognised in the Hawaiian Islands during July, 1912, supposedly from Japan. This paper not only describes the successful methods used in establishing this wasp, but other valuable notes on death-factors. of the beetle are given—i.e., other parasitic and predaceous insects, fungi, &e. Bauuou, H. A.—Feeding Habits of the Parasites of the Hardback Grubs. The Agr. News, Barbados, xvii, 250. Advocates nectar-bearing plants for attraction of wasps, which parasitize cane-grubs. The writer cites the successful work done with these wasps in Mauritius. (40) (45) (46) 27) 1918. 1918. OG: 1919. 1919. OO: HOUS TOTO, is)t8). 1920. 1921. NATURAL ENEMIES OF SUGAR-CANE BEETLES. 47 CHARMOY, D. p’E. pe—The Importation of Tiphia parallela from Barbados to Mauritius. Dept. Agr. Mauritius, Scientific Ser. Bull. No. 6. TnuincwortH, J. F.—Monthly Notes on Grubs and other Cane Pests. Qld. Bur. Sugar Exp. Sta., Div. Ent. Bull. No. 7. Notes on Musecardine fungus (p. 10), parasites (pp. 12, 14-16, 19-21, 29), bandicoot and pouched mice (p. 22). Davis, J. J—Contribution to a Knowledge of the Natural Enemies of PhyWophaga. State of Illinois Nat. Hist. Survey Bull. Urbana, xiii, article v. Life-histories are given of the various parasitic and preda- ceous insects attacking the Melolonthid beetles of the genus Phyllophaga. Particulars are also given of other diseases caused in white grubs by Nematodes, Protozoa, bacteria, and fungi, with a list of the birds, mammals, and amphibia that prey upon them. Tuurncwortu, J. F.—A Successful Method of Breeding Parasites of White Grubs. Journ, Econ. Ent. xii, 455, Inuinewortu, J. F.—Monthly Notes on Grubs and other Cane Pests, series 2. Qld. Bur. Sugar Exp. Sta. Div. Ent. Bull. No. 8. Discusses parasites, and the value of nectar-bearing flowers. Jarvis, E.—Insect Friends of the Cane-grower. Qld. Agr. Journ, xii, 301. A brief compiled summary of the enemies of the cane-grubs. Murr, F.—The Progress of Scolia manile Ashm, in Hawaii. Ann, Ent, Soe: Annis scinsellial Records the successful reduction of Anomala orientalis by means of the above parasite. WiuuiAms, F. X.—Philippine Wasp Studies. Hawaiian Sugar Planters’ Assn. Ent. Ser. Bull. No. 14. Among many others, gives excellent life-history studies of various species of Scoliide and Thynnide. WituiAMs, F. X.—A Note on the Habit of Lpactiothynnus opaciventris Turner, an Australian Thynnid wasp. Psyche, xxvi, 160. Lamellicorn grubs paralysed, just as the Scolias sting their prey, and in one case an egg was attached to the venter of the grub. InLInGwortH, J. F.—Monthly Notes on Grubs and other Cane Pests, series 3. Qld. Bur. Sugar Exp. Sta. Div. Ent. Bull. No. 10. Discusses various natural factors in the control of cane- grubs, &e. TuuwwewortH, J. F.—A Study of Natural Methods of Control for White Grubs. Qld. Bur. Sugar Exp. Sta. Div. Ent. Bull. No. 12. Results of experiments with the green Muscardine fungus and bacterial diseases for grub control. ANTHONY JAMES CUMMING, Government Printer, Brisbane. PuatE Il.—Grubs killed by the fungus Metarrhizium, anisoplie Metsch., showing successive stages in the development of this disease organism, as it gradually changes the tissues of the grub into myriads of grey-green spores. Ale ois . 2a. 5 ek OU sue PLATE IIJ.—PrREDACEOUS ENEMIES OF CANE GRUBS. Promachus doddi Bezzi, female. Natural size. Egg-mass of same, taken from leaf of sugar-ecane. Natural size. Same, enlarged. Separate egg of same, more enlarged, showing segmented larva doubled up inside. Grub paralysed by newly hatched Asilid maggot, attached to skin on thorax. Maggot; full-grown. Asilid pupa. Larva of Agrypnus mastersi Pascoe. The parent beetle, a skip-jack. Plate II E. Jarvis. Del. PLATE IV.—STAGES IN THE Lire HISTORY OF CAMPSOMERIS RADULA F'ABR. Fig. lt bo Adult female. Naturai size. Adult male. Natural size. . Vertex, showing the three characteristic yellow spots. X_ 5. . Labrum, plain, which is characteristic of this species. xX 5. :, Pygidium, with characteristic yellow on proximal portion. X 7. Paralysed grub, showing characteristic position of the wasp egg. Natural size. The egg, two views. Magnified. A male larva feeding; age seven days. Natural size. A female larva, ten days old, still feeding. Natural size. . The cocoon of the wasp, in cell. Natural size. The pupa of same, in cocoon. X 2. Plate W Del. E. Jarvis. Fig. Fig. eo PLATE V.—CoMMON SCOLIIDS OF THE CaiRNS DISTRICT. Campsomeris tasmaniensis Sauss., female, the usual marking. Natural size. Male of same. Natural size. . Showing the two characteristic small yellow spots. x 5. . Pygidium with no yellow, wiich is characteristic of this species. x 9. . Labrum, showing characteristic dark spot in centre. 5. C. tasmaniensis, a variation in the marking of the female. Natural size. Campsomeris carinifrons Turner, female. Natural size. Scolia formosa Guer., female. Natural size. Campsomeris ferruginea Fabr., female. Natural size. Plate V Del. E. Jarvis. PLATE VI.—COMMON SCOLIIDS AND THYNNIDS OF THE CAIRNS DISTRICT. Vig. 1. Scolia soror Smith, female. Natural size. Fig. 2. Male of same. Natural size. Fig 3. Tiphia intrudens var. brevior Turner, female. X_ 3. Fig. 3a. Outline, showing natural size of above. Fig. 4. Thynnus pulehralis Smith, male. Natural size. Fig. 5. Zaspilothynnus verialis Turner, male. Natural size. Plate VI Del. E. Jarvis. PLATE VII.—HYPERPARASITES OF SCOLIID WASPS. Fig. 1. Hyperalonia funesta Walker. X 2. Fig. 2. A pupa of one of these flies. & 2. (After Davis.) Fig. 3. A Rhipiphorid beetle. X 3. (After Davis.) / PLATE VIII.—APPARATUS USED IN BREEDING CAMPSOMERIS WASPS. At the left, the small tins with covers, in which the female wasps were kept im soil while parasitizing grubs. The parasitized grubs are shown in the top tray; resting on this is the wooden moela which was used to form the rows of depressions for the grubs. At the right, the glass tubes from which the wasps were secured as fast as they emerged. feiegy 2% eee ae sd eos SB apy Nig Sepia MM inv ih Hh | \i\}| WW W Ht | | MM MW Ml i NA NV WIV i MN Hi | WIN || WA Ml {I Ni i iH WAL NI