90% percent of the pollination in cross-pollinated crops like oil seeds, vegetables, fruit crops and some field crops is affected by honey bee alone. It is extremely worrying to see a mass decline of bee population in the past few years. This sudden and dramatic decline in bee population is called Colony Collapse Disorder (CCD).

Hence, the knowledge of relative safety of insecticides during flowering stage is essential to obtain the maximum benefit from the bee population. By definition, insecticides are harmful to insects but individual products vary greatly in their toxicity to bees.

An ideal insecticide should be effective against target pests but safe to pollinators and beneficial insects. In this article Endosulfan will be discussed with special reference to the CCD.

Bees are considered as the most effective pollinators compared to all other insects. Honeybee pollination increases crop yields by many-fold as shown below.

Insecticides used for the control of insect-pests are hazardous to honeybees also. When these insecticides are sprayed on blooming crops, they result in mortality of honeybees. This results in poor pollination and hence reduces the yield. Hence, it is of paramount importance that relatively safe insecticide should be used during flowering stage of the crop. The graph below indicates relative safety of various insecticides to honeybees.

Source: I.S. Gour & B.L. Pareek, 2004. "Effect of insecticides on the incidence of honey bee, Apis cerena indica Fab. On mustard bloom under semi-arid region of Rajasthan" Madras Agric. J. 91 (7-12): 430-432

The results presented in the above graph indicate that Endosulfan is one among the least toxic insecticide with reference to honeybee. In fact Endosulfan is next only to Neem extract in terms of its safety to honeybee. While other insecticides, including recently introduced neonecotinoids, are highly toxic to the honeybee.

It is clear that honey bees are a fundamental part of sustainable agriculture. Hence, protecting the honey bee is of paramount importance. Using a relatively safer insecticide like Endosulfan is desirable so as to ensure that honey bee population across the world does not decline.