Inter‐and intra‐specific effects of the mandibular gland secretion of larvae of the Indian‐meal moth, Plodia interpunctella

Abstract

The effects of the mandibular gland secretion of larvae of Plodia interpunctella (Hubner) on the behaviour of conspecific larvae and on its parasitoid, Nemeritis canescens (Gravenhorst) were studied in open chambers and in an olfactometer. The secretion is deposited in the form of droplets on the silk while it is being spun, and as irregular patches on the substratum. Plodia larvae presented with a choice between fresh food and food contaminated with mandibular gland secretion chose fresh food. Those provided with contaminated food only, chose this in preference to starvation. The secretion also caused 'attraction' and stimulation of oviposition movements in female Nemeritis, leading to increased parasitization. The stimulatory effect of the droplets was remarkably persistent and could be detected after storage for at least 5 years at room temperature as well as at 4°C or -7°C. Chemical analysis indicated the presence of two components, the major with an Rf value of 0.6 (empirical formula C&IwO4), and the other with an Rf value of 0.8 (empirical formula C22H3803).Observations on the effect of droplets of mandibular gland secretion on the behaviour of Nemeritis, and on the resulting parasitization were made at 25 f 0.5"C under a ceilingmounted fluorescent light; adult females 3-5 days postemergence were used exclusively. Observations on Plodia larvae were made at the same temperature in semidarkness with the aid of a 40-W red lamp positioned 60 cm from the olfactometer chamber; fifth instar, pre-wandering larvae were used. Response of Plodia larvae to mandibular gland secretion MethodsLarval responses were tested in an olfactometer (Fig. la) based on the design of Varley & Edwards (1953). It was constructed from two sheets of perspex separated by six shallow walls of perspex arranged in the form of a hexagon. The walls were permanently fixed to 0307-6962/80/0600-0165 $02.00 0 1980 Blackwell Scientific Publications 165 11 C, chamber; H, hexagonal plate; B, base of the chamber. The height of the walls of the chamber was 0.8 cm. Three 2.1 cm holes are drilled in the top: one near the outlet for the insertion of the larvae (i.e. at start of tracks in Fig. lb), and one over each odour source for insertion of test materials (i.e. above the squares). During operation these holes were sealed. Stimuli in Figs. l b , 1 and 2 were clean food versus contaminated food; in 3 and 4 , ether extract of cocoons (i.e. plus mandibular gland secretion) versus clean filter paper.

Responses of Microplitis croceipes to host and nonhost plants of Heliothis virescens in a wind tunnel

“…Odor from H. virescens larvae did not trigger flight behavior of M. croceipes in wind tunnel and olfactometer studies (Eller et al, 1988;Rotheray, 1981), in contrast to the finding by Elzen et al (1987) that H. virescens larvae were attractive to the HeIiothis parasitoids, C. sonorensis and M. croceipes; Thorpe & Jones (1937), Monteith (1955), Mossadegh (1980), Nettles (1980), and the present study demonstrated host attraction to parasitoids.…”

Cocoon‐spinning larvae of Oriental fruit moth and Indianmeal moth do not produce aggregation pheromone

“…IMM larvae develop within, and compete for, the same resource, sometimes even cannibalizing each other ( Bjørnstad et al , 1998 ). Throughout their larval development, they produce a spacing pheromone that helps regulate colonization densities in the resource ( Mossadegh, 1980;Howard & Baker, 2004 ). IMM larvae may lack the physiological mechanisms to cease production of the spacing pheromone, and/or to produce and respond to aggregation pheromone in their final larval instar prior to pupation.…”

“…J., personal observation). Pre-wandering fifth-instar larvae repel each other by semiochemicals derived from droplets of mandibular gland excretions ( Mossadegh, 1980 ), providing evidence for pheromonal communication among pre-wandering larvae. Wandering-stage larvae have the same semiochemicals at a different ratio ( Howard & Baker, 2004 ) but the response to them has not yet been investigated.…”

New 2-Acylcyclohexane-1,3-diones: Kairomone Components against a Parasitic Wasp,Venturia canescens,from Feces of the Almond Moth,Cadra cautella,and the Indian Meal Moth,Plodia interpunctella

“…3 -5) The presence of two compounds in the glands of P. interpunctella with the molecular for-mulae of C24H4004 and C22H3S03 was concluded from high resolution mass spectrometry, and their structures were suggested to be 4-hydroxy-2-0Ieoylcyclohexane-1 ,3-dione and 2-palmitoylcyclohexane-I,3-dione (I) from their molecular formulae. 6 ) Two major kairomone components have also been detected in the feces of P. interpunctella larva, and structures were identified as compound I and 2-0Ieoylcyclohexane-1 ,3-dione. 7) In this study, the presence of 2-acylcyclohexane-I,3-dione homologues was surveyed in the feces of P. interpunctella, C. cautella and also in the rearing medium (rice bran).…”