Biologi dan Neraca Hayati Kumbang Cryptolaemus montrouzieri (Mulsant) (Coleoptera: Coccinellidae) pada Kutu Putih Singkong

Abstract

Indonesia merupakan produsen singkong (Manihot esculenta) terbesar keempat di dunia setelah Brazil, Nigeria, dan Thailand. Kutu putih Phenacoccus manihoti merupakan hama paling berbahaya pada singkong yang berpotensi menimbulkan serangan berat. P. manihoti mendapat nutrisi dengan cara menghisap cairan dari tanaman dan menyerang bagian pucuk tanaman. Cryptolaemus montrouzieri diketahui merupakan musuh alami yang sangat efisien memangsa kutu putih dalam jumlah banyak. Penelitian dilakukan di laboratorium dengan tujuan untuk mengetahui (1) masa perkembangan pradewasa, lama hidup imago dan keperidian, (2) parameter neraca hayati predator C. montrouzieri pada tanaman singkong. Hasil penelitian menunjukkan periode inkubasi telur 4,01 hari. Rata-rata perkembangan masing-masing larva instar 1, 2, 3 dan 4 berturut-turut adalah 3,28; 4,15; 4,67 dan 4,79 hari. Prapupa dan pupa masing-masing berlangsung 1,41 hari dan 6,26 hari. Total masa perkembangan masing-masing pradewasa jantan 28,91 hari dan betina 28,57 hari. Masa hidup imago jantan adalah 26,12 hari, sedangkan betina 25,45 hari. Jumlah telur yang diletakkan oleh seekor betina rata-rata 168 butir. Studi neraca hayati menunjukkan laju reproduksi kotor (GRR) 61,843 betina per generasi. Laju reproduksi bersih (R0) 37,745 betina per betina per generasi. Laju pertambahan instrinsik (r) 0,072 betina per betina per hari. Rataan lama generasi (T) 50,145 hari. Waktu yang dibutuhkan populasi untuk berlipat ganda (DT) adalah 9,572 hari.

Indonesia is the fourth largest cassava (Manihot esculenta) producer in the world after Brazil, Nigeria, and Thailand. Mealybug Phenacoccus manihoti is the most dangerous pest in cassava that has the potential to cause severe damage. P. manihoti gets nutrients by sucking fluid from the plant and attacking the shoots of the plant. Cryptolaemus montrouzieri is known to be a natural enemy that is very efficient in preying on mealybugs. The research was conducted in the laboratory with the aim to determine (1) the period of preadult development, adult life span and pupilage, (2) life table parameters of C. montrouzieri preys on mealybug. The results showed that the egg incubation period was 4.01 days. Mean developmental periods for 1st, 2nd, 3rd, and 4th instar larvae were 3.28; 4.15; 4.67 and 4.79 days, respectively. Prepupae and pupae lasted for 1.43 days and 6.26 days, respectively. The total developmental period of male preadult was 28.91 days and female preadults 28.57 days, respectively. The life span of the adult was 26.12 days for males and 25.45 days for females. The number of eggs laid by a female averaged 168. The life table study showed the gross reproductive rate (GRR) of C. montrouzieri was 61.843 females per generation. The net reproductive rate (R0) was 37.745 females per female per generation. The intrinsic rate of increase (r) of C. montrouzieri was 0.072 females per female per day. Average generation length (T) of C. montrouzieri was 50.145 days. The time taken for the population to double (DT) was 9.572 days.