LABORATORY STUDIES ON PERISTENUS PALLIPES AND P. PSEUDOPALLIPES (HYMENOPTERA: BRACONIDAE), PARASITOIDS OF THE TARNISHED PLANT BUG, LYGUS LINEOLARIS (HEMIPTERA: MIRIDAE)

1976 ◽  
Vol 108 (8) ◽  
pp. 815-821 ◽  
Author(s):  
K. P. Lim ◽  
R. K. Stewart

AbstractDevelopment of P. pallipes, from egg to emerged larva, in the tarnished plant bug lasts 24.49 ± 2.38 days at 25 °C/16 h and 20 °C/8 h and 77 ± 5% R.H. with 16 h illumination.Eggs of P. pseudopallipes need 72–96 h to hatch under the above-cited regime. At least three distinct larval stages can be recognized without special staining procedures. The first instar larva is a caudate-mandibulate type. The second larval stage is acaudate and lives in the host haemocoele. The third larval stage is also acaudate and emerges from the host. The pupa is an exarate type diapausing in a cocoon. P. pseudopallipes is an arrhenotokous species. The longevity of the adults in the laboratory is about 16 days. The adult oviposits into the host abdomen.Survival of diapausing pupae is better at 16 h photophase than at 8 h photophase.

2014 ◽  
Vol 11 (2) ◽  
pp. 943-951
Author(s):  
Baghdad Science Journal

The following dilution 5×10-1, 10-1, 10?2 , 10-3 gm/L for the indigenous isolate of Bacillus thuringiensis bacteria and the commercially isalate were used for experiments against the different stages of fig moth of E.cautella which exposed by filter paper method. The results showed that mortality of larval stages was increased with the increasing concentration of the biocide, in addition to increase in the mortality of the larval stages reached to the highest percentage in the third days of treatment of the larval stage in comparison with the first and second days of exposure. The results also showed that the sensitivity of larval stages was increased in first and second instars while reduced in the last instars .The high percentage of first instar mortality for the indigenous isolate in the concentration of 5×10-1 was 72.8% , while the low percentage of mortality showed in the concentration of 5×10-1 for the fifth instar larvae which was 13.3% in third days of treatment while a high percentage of mortality was showed for the first instar larvae for the commercially isulate in the concentration of 5×10-1 was 59.4% Furthermore, low percentage of mortality was shown in the concentration of 5×10-1 in fifth instar larval which was 8.3% in the third days of treatment. The results also showed that the indigenous isolated was more effective than the commercially produced bacteria for killing larval instars of fig moth E.cautella .The total percentage of larval instar mortality reached to 44.5 % after the third days of treatment in concentration 5×10-1 in the indigenous isolate , and it was 33.8 % in the commercially produced bacteria .


1968 ◽  
Vol 100 (2) ◽  
pp. 202-206 ◽  
Author(s):  
Louis F. Wilson

AbstractThe willow beaked gall midge, Mayetiola rigidae (Osten Sacken), is univoltine in Michigan. Adults emerge from bud galls on Salix discolor Mühl. and other willows on mornings of warm days in early April. Eggs are laid singly on or near the buds of the host. Head capsule measurements indicate three larval instars. The last two instars each possess a spatula. The first-instar larva emerges in late April and penetrates the soft bud tissues. The gall begins to develop at the beginning of the second instar in mid-May. The third instar appears in early July and continues to enlarge the gall until fall. Prior to overwintering, the larva lines the inner chamber of the gall with silk and constructs one to seven silken septa across the passageway. Pupation occurs in mid-March. The gall deforms the stem and occasionally a galled branch dies or breaks off.


1972 ◽  
Vol 104 (9) ◽  
pp. 1445-1456 ◽  
Author(s):  
J. J. Drea ◽  
R. J. Dysart ◽  
L. W. Coles ◽  
C. C. Loan

AbstractMicroctonus stelleri Loan is described as a new species. This euphorine braconid occurs in France, Germany, Sweden, and Russia. It is umvoltine and its only known host is the alfalfa weevil, Hypera postica (Gyllenhal). In the spring the mature parasite larva issues from the overwintered adult host and forms a white cocoon in the ground litter. In about 2 weeks the adult parasite emerges, mates, and oviposits in larva of the alfalfa weevil. The parasite egg hatches and the first-instar larva remains within the host until the following spring. In northern France M. stelleri was the dominant parasite in overwintering adults of H. postica. Parasitism ranged from 0 to 13% though it was usually less than 6%. Laboratory studies showed that M. stelleri females live longer, have a higher rate of oviposition, and parasitize more hosts than females of M. colesi Drea, a parasite of the weevil in the United Slates. A technique is described for the recovery of M. stelleri from adult alfalfa weevils. From 1966 to 1970, 4387 parasites were imported from France and released at 24 localities in the United States.


2017 ◽  
Vol 57 (1) ◽  
pp. 215-227 ◽  
Author(s):  
Andrés Campoy ◽  
Celeste Pérez-Bañón ◽  
Tore R. Nielsen ◽  
Santos Rojo

Abstract The flower- or hoverflies (Syrphidae) and particularly the subfamily Eristalinae, are known by their importance as pollinators in both natural and agro-ecosystems. Similar to other saprophagous eristalines, the larvae of Eristalis Latreille, 1804 are characterized by an elongated anal segment and a telescopic breathing tube. These features have given them the common name of rat-tailed maggots and allow them to develop in liquid or semi-liquid media loaded with decaying organic material. This paper presents the first description of the egg and the third-instar larva of the boreal species Eristalis fratercula (Zetterstedt, 1838). Morphological studies are presented based on cryo-scanning electron microscopy (cryo-SEM). After comparison with all other known species of the genus Eris-talis with described preimaginal morphology, we conclude that main diagnostic character of E. fratercula is the presence of long branched spicules located in the upper margin on the lateral lips. Finally, we provide an updated key that includes the 15 Eristalis species whose third larval stages have already been described.


1990 ◽  
Vol 68 (5) ◽  
pp. 1000-1004 ◽  
Author(s):  
J. C. Thireau ◽  
J. Régnière ◽  
C. Cloutier

The immature stages of Meteorus trachynotus Vier., developing in larvae of Choristoneura fumiferana (Clem.), are described. The egg of M. trachynotus is of the stalked type. There are three larval stages. The first instar has a caudal appendage which stops growing in the second instar and is lost when the larva exits from the host in the third instar. Only the first and third instars have sclerotized structures. The head region of the first instar bears a pair of hooklike appendages which are described for the first time. Cephalic sclerites of the last instar larva of other species of Meteorus are compared with those of M. trachynotus. The average duration of immature development at 23 °C was 18 days, the egg stage lasted 3 days, the first, second, and third instars lasted 5, 2.5, and 2.5 days, respectively, and the pupal stage lasted 5 days.


1988 ◽  
Vol 19 (3) ◽  
pp. 381-391 ◽  
Author(s):  
Anders N. Nilsson

AbstractA lectotype is designated for Agabus setulosus (J. Sahlberg, 1895), a rare rheophilous dytiscid known mainly from northern Fennoscandia. The larval instars are described for the first time, based on material from northern Sweden. The first-instar larva is characterized by the presence of two dorsal spines on each femur and a pair of mediodorsal setae on last abdominal segment; both characters are seemingly unique among Agabus. The third instar differs from all other Palaearctic Agabus species in the complete sclerotization of the ring-like abdominal segment 6. The biology of A. setulosus is described from a Swedish population; semivoltine life cycle with overwintering eggs laid in summer followed by adult overwintering prior to breeding is suggested.


2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Donald B. Thomas ◽  
John A. Goolsby

The larval stages ofLasioptera donacisCoutin consist of three instars which develop within the mesophyll of the leaf sheaths ofArundo donax(L.) (Poaceae). The larvae feed aggregatively on mycelia of an ambrosia fungus. The third instars are similar to other members of the genus except for a three-pronged spatula (typically two-pronged) and five lateral papillae (typically four) and with a nonbristled first instar. A related species,L. arundinis(Schiner) which breeds on fungus inPhragmites(Poaceae), also has a three-pronged spatula and five lateral papillae but has a bristled first instar. The third instar ofL. donacishas a feeding and a nonfeeding prepupal stage. Papillae associated with the spatula are sensory organs, sensilla chaetica, sensilla trichodea, and sensilla ampullacea, perhaps related to extraoral digestion of the fungal mycelia. Pupation occurs in the host plant within a silken cocoon. Egression of the adult is through an escape hatch excavated by the third instar.


1970 ◽  
Vol 1 (4) ◽  
pp. 315-320
Author(s):  
Reinhold Charpentier

AbstractMorphological, cytochemical and developmental studies were undertaken of a new "double" type of proteinaceous globules in fat body and haemolymph of Aphodius constans Duft. The homogeneous globules first appear in the late first instar or the early second instar larva—i.e. earlier than in other insects. In the middle of the third instar the central region of the globules begins to differentiate into a core, much resembling the polyhedron of a nuclear insect virus. The cores are, however, not a pathological phenomenon, but constitute normal reserve substances, present in all individuals, especially in the prepupa, the pupa and the early adult. Both the core and the periphery of the "double" globules, as well as "empty" globules from second and third instar larvae, contain proteins and ribonucleic acid, although the cytochemical reactions of the core was always the most intense. Neither lipids, carbohydrates, desoxyribonucleic acids nor uric acid are deposited inside the globules. There is no membrane around the globules.


Parasitology ◽  
1961 ◽  
Vol 51 (3-4) ◽  
pp. 269-294 ◽  
Author(s):  
Dorothy J. Jackson

The immature stages of Caraphractus cinctus Walker are described.Four larval stages have been observed which may correspond to three or four instars. In no stage have mandibles been observed.The first-instar larva is elongated and active. In the second-instar oral lobes are present. In the next stage the larva becomes shapeless and rather transparent. In the last stage the wall of the mid-gut shows conspicuous opaque spots which consist of single cells containing spherical concretions, probably the products of excretion.These concretions later become free in the gut of the pupa and are discharged in the meconium when the imago emerges from the host egg.The effects of parasitism on the host eggs of different ages is discussed. In newly laid host eggs all the contents are consumed by the parasitic larvae. In advanced eggs of Agabus the egg of Caraphractus is laid in the mid-gut of the host embryo where the parasitic larva develops, the hard parts of the host larva remaining intact. Parasitism in advanced eggs of Dytiscus is rarely successful.The larvae of other Mymaridae are discussed and their main features compared. The first-instar larva of Caraphractus does not correspond to any of the previously described types of mymarid larvae.The seasonal history is described, with the sequence of hosts parasitized throughout the year. From four to six generations of Caraphractus have been bred indoors during the year. The winter is passed as a diapausing prepupa. In some cases diapause may be prolonged. Fertility is high: 121 imagines have been bred from one female of Caraphractus.I have much pleasure in acknowledging my gratitude to the late Dr W. D. Hincks for his kindness in reading the typescript of this paper: the comments by such a well-known authority on Mymaridae have been most valuable. I am very grateful to Mr O. Bakkendorf for allowing me to reproduce several of his figures of Mymarid larvae from the valuable work he devoted to the biology of Danish hymenopterous egg-parasites. I am also grateful to Miss B. A. Trott of the Commonwealth Institute of Entomology for the help she has so kindly given me with references.


2014 ◽  
Author(s):  
Bruno A S de Medeiros ◽  
Daniela C Bená ◽  
Sergio A Vanin

Weevils are one of the largest groups of living organisms, with more than 60,000 species feeding mostly on plants. With only one exception, their described larvae are typical plant-feeders, with mouthparts adapted to chewing plant material. Here we describe the second case of a weevil with early-instar larvae adapted to killing conspecifics. We have studied the life history of Anchylorhynchus eriospathae G. G. Bondar, 1943, a species whose immatures feed internally on palm flowers and fruits. We provide detailed descriptions of all immature stages, including the extremely modified first-instar larva. Unlike other weevils and later instars, this stage exhibits a flat body with very long ventropedal lobe setae, a large and prognathous head with a gula, and falciform mandibles, each with a serrate retinaculum, that are used to fight with and eventually kill other first-instar larvae. We also provide biological notes on all stages and the results of behavioral tests that showed that larval aggression occurs only among early life stages. Finally we show that adult size is highly dependent on timing of oviposition. This specialized killer first instar probably evolved independently from the one other case known in weevils (in Revena rubiginosa). Interestingly, both lineages inhabit the same hosts, raising the possibility that both intra- and inter-specific competition shaped those phenotypes. Given the scarcity of knowledge on early larval stages of concealed insect herbivores, it is possible that our findings represent an instance of a much broader phenomenon. Our observations also allowed us to conclude that Anchylorhynchus eriospathae and A. hatschbachi G. G. Bondar, 1943 are actually the same species, which we synonymize here by considering the latter as a junior synonym (new synonymy).


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