Histopathological, biological and biochemical effects of lufenuron on Schistocerca gregaria (Orthoptera : Acrididae)‎

الملخص EN

Locusts are considered a dangerous insect attacking almost the important economic crops.

One of these injurious insects is the desert locust Schistocerca gregaria Forskål (Orthoptera: Acrididae), which has a great economic importance in Egypt.

Newly moulted second, third, fourth and fifth instar nymphs of the desert locust, S.

gregaria was sprayed with the chitin synthesis inhibitors cymax, lufenuron in a recommended dose 40ml/100L.

water to assignment the percentages of mortality, malformation and prolongation in life period also to evaluate histological changes in testis compared with the normal histological structure of control testis and determine total protein.

Mortality percentages were 26.67, 23.33, 16.67, 10 and 10% for second, third, fourth, fifth nymphal instars and adult insects respectively, but were 40, 46.67, 36.67 and 36.67% through moulting.

Also, malformation percentages were 30, 23.33, 20 and 23.33% in second third fourth fifth nymphal instars respectively.

The life period of the treated nymphs reached at 7.33, 8.33, 8.67 and 10.33 days to second, third, fourth and fifth nymphal instar, respectively, but normally the duration of life to untreated nymphs were 5.67, 6.33, 7 and 7.67 days, respectively.

The treatment induced variable histological changes in the testis.

Effects on the testis were manifested by cytoplasmic vacuolation.

Also, the treatment caused many ultrastructural changes in male germ cells including scattered vacuoles, degeneration, ad-electron mitochondria and many vacant areas.

The levels of haemolymph protein decreased after 5,10 and 15 days when the males were treated for one day old and reached 61.25, 40.53and 26.59 mg/100 ml, respectively as compared with 79.86, 75.42 and 82.03 mg/100ml of untreated males, respectively.

Those changes may lead to infertile males.