Incidence and management of coconut scale, Aspidiotus destructor signoret (Hemiptera: Diaspididae), and its parasitoids on mango (Mangifera sp.)

• Aspidiotus destructor is a serious problem for the mango growers from July to December in D. I. Khan.
• Among four mango varieties investigated, Langra is most affected by A. destructor.
• Natural enemies play vital role in the control of scale insects.
• Imidacloprid and petroleum oil gave excellent result against A. destructor while pyriproxyfen proved effective for long term use.
• Thiamethoxam had delayed effect while bifenthrin had a quick knock down effect for few days against scale insects.

Populations of coconut scale, Aspidiotus destructor Signoret (Hemiptera: Diaspididae), and its parasitoids were surveyed on 4 mango cultivars in the southern district of Khyber Pakhtunkhwa, Pakistan, from July 2011 to June 2013. The populations of A. destructor built up in July and continued for 6 consecutive months reaching a peak in November 2011 (54 scales/leaf) and in October 2012 (44 scales/leaf). Two parasitoids, Aphytis melinus DeBach (Hymenoptera: Aphelinidae) and an Anagyrus sp. (Hymenoptera: Encyrtidae) were first observed in August, reaching peaks in November 2011–12 and 2012–13 (13.6 and 16.3% parasitism) and December 2011–12 and 2012–13 (14.2 and 14.9% parasitism), respectively for the two species. The efficacy of two winter oils, one IGR (pyriproxyfen 10.8 EC), one organophosphate (profenofos 500 EC), one pyrethroid (bifenthrin 10 EC), and two neonicotinoid insecticides (imidacloprid 20% SL and thiamethoxam 25 WP) were evaluated at recommended rates against 1st and 2nd instars and mature A. destructor on nursery plants and mature mango trees. In both cases, the highest A. destructor mortalities were recorded with petroleum oil, imidacloprid and pyriproxyfen. Thiamethoxam was effective after 14 days (70–80 % scale insect mortality) while bifenthrin showed good results against all life stage in the first 14 days. For management of A. destructor, parasitoids may be conserved by using oils and insect growth regulators (IGRs) while systemic insecticides may also be used in the case of severe infestations. The 1st spray must be applied in early August (before parasitoids emergence), the 2nd spray in October, as one spray controls the pest for one month. One dormant spray may be applied in February after pruning of infested leaves and branches to clean the plants from A. destructor for the next season.