EFFECTS OF JUVENILE HORMONE ANALOGUES ON THE METAMORPHOSIS OF BEETLESTROGODERMA GRANARIUM(DERMESTIDAE) ANDCARYEDON GONAGRA(BRUCHIDAE)

Abstract

EFFECTS OF JUVENILE HORMONE ANALOGUES ON THE METAMORPHOSIS OF BEETLES TROGODERM. I GRANARITM ( DERMESTIDAE) AND CARYEDOX CONAGRA (BRl'CIIIDAE) AIOXIK M. METWALLYi AND FRANTISEK SEHXAI. Institute of Eiitninoloi/y, Czechoslovak . Icadeiny of Sciences, I'r<ii/in' Several authors for example Bowers and Thompson (1963) in a paper on Tenebrio inolitor (Tenebrionidae ) . Slama and associates in a study on Derinesles 'I'lil/^iiuis (Dermestidae), and De Wilde ( 1 () 71 I in a note concerning Leptinotarsa decemlineata (Chrysomellidae) demonstrated that application of juvenile hormone analogues (JHa) to freshly molted pupae (if bectlo inhibits imaginal differentiation. Detailed description of the effects elicited, however, is available only for the Hour beetle, l^encbrio inolitor ( Rose, \\'estermann. Trautmann. Schmralek and Klauske 1969). This species is also the only beetle in which the effects of J I la on the larvae were studied (Schmialek, 19(>3). Therefore, in the present study we have examined in detail the effects of J I la on both the larval-pupal and pupal-adult transformation of representatives of the coleopteran families Dermestidae and Bruchidae.The dermestids and bruchids differ from one another in many features, and it was intriguing to compare their responses to JHa. Both families include serious TROGODERMA GRANARIUM (DERMESTIDAE) AND CARYEDON GONAGRA (BRUCHIDAE)." The Biological bulletin 144, 368-382.

Juvenoid-induced supernumerary larval instars in certain stored grain insects

“…Thus in T.granarium while Metwally and Sehnal (1973) found that only the early part of the life of the last larval instar is sensitive to juvenoid action, Srivastava and Srivastava (1974) in the same insect and Ishaya and Yablonski (1976) in Tribolium castaneum reported that the period of sensitivity extends to almost the end of the life of the instar. Similarly while Bhatnagar-Thomas (1972) and Metwally and Sehnal (1973) could not correlate the dose of juvenoid with the number of supernumerary moults in T.granarium, Srivastava and Srivastava (1974) found a direct relationship between the two. Metwally and Sehnal (1973) did not report growth in supernumerary instars but Bhatnagar-Thomas (1972), Srivastava and Srivastava (1974) and Ishaya and Yablonski 0976) noted such growth.…”

“…Similarly while Bhatnagar-Thomas (1972) and Metwally and Sehnal (1973) could not correlate the dose of juvenoid with the number of supernumerary moults in T.granarium, Srivastava and Srivastava (1974) found a direct relationship between the two. Metwally and Sehnal (1973) did not report growth in supernumerary instars but Bhatnagar-Thomas (1972), Srivastava and Srivastava (1974) and Ishaya and Yablonski 0976) noted such growth.…”

A study of pupal-adult intermediates produced with juvenoid treatment ofSpodoptera litura Fabr. pupae

“…Thus, according to this view, in order to be effective an increased titre of JH{JHA should be available in the insect system and it should start action before the process of cellular differentiation is set into motion, probably at a time when the gene sets are being reprogrammed for a new developmental cycle. Metwally and Sehnal (1973) have observed that even the most severely affected specimens of Trogoderma resulting from pupal treatment, displayed slightly pigmented eyes, outlines of segmentation of appendages, and most important of these, the absence of pupal hair. The maximally affected individuals of Caryedon also resembled normal pupae except that their eyes and appendages showed adultlike differentiation.…”

“…In S. bullata, Srivastava and Gilbert (1969) noted that the thorax is the first to become refractory to hormone during pharate adult life followed by the head and then the abdomen. Gilbert and Schneiderman (1960) in A. polyphemus and Metwally and Sehnal (1973) in T. granarium and C. gonagra found that external genitalia and the abdomen as a whole were the first sensitive parts, then the thoracic structures and finally the appendages and mouth parts. In many species of endopterygotes, Slama (1971) had noted that the epidermal cells of the wing lobes, thoracic and head appendages, and external genitalia lose their sensitivity to juvenoids sooner than the epidermal cells of abdomen.…”

“…Several workers have noted the production of pupal-adult intermediates in endopterygote insects by treating pupae with juvenile hormone or its various analogues (Sarcophaga bullata, Srivastava and Gilbert 1969;Bhaskaran 1972;Tenebrio molitor, Critchley and Campion 1971;Trogoderma granarium, and Caryedon gonagra, Metwally and Sehnal 1973;Trogoderma granarium, Srivastava and Srivastava 1974 ;Ceratitis capitata, Daoud and Sehnal 1974;Ephestia kuhniella, Tan 1975 ; Cylas formicarius, Ram et al 1980). In Sarcophaga bullata, Srivastava and Gilbert (1969) concluded that the thorax is the first to become refractory to the hormone during pharate adult life, followed by the head and then the abdomen ; and that the age of pupa is the most important factor which influences production of intermediates.…”