Dr Jim Cullen's research background is in entomology and population ecology, with an emphasis on biological control of insect pests and weeds, the latter requiring a prolonged excursion into plant pathology during his career with Commonwealth Scientific and Industrial Research Organisation (CSIRO). This also included two uplifting educational experiences, the first liaising with the Industries Assistance Commission on cost: benefit analyses of agricultural research, plus a ‘legal period' of eighteen months when he was responsible for coordinating CSIRO's response to the High Court injunction on the program against Paterson's Curse. He has published on biological control, insect physiology, plant pathology, weed management, agricultural economics and legal issues in agriculture.

Jim was responsible for several weed and insect biological control projects, ran the CSIRO European Laboratory in France from 1983 to 1987 and was a member of, or chaired several Standing Committee of Agriculture technical committees on biological control and weeds research. He led much of the early discussions with Australian Quarantine and Inspection Service (AQIS) to develop protocols for the introduction of biological control agents and was responsible for the original design of CSIRO's high security quarantine facility in Canberra.  Jim was a member of the Australian Weeds Committee for many years and coordinated the successful proposal for the first Weeds CRC. Following the Nairn Review of Quarantine, he was appointed a member of the Quarantine Exports and Advisory Council and worked with AQIS and the Import Risk Analysis Review system at various times.

Jim was leader of the CSIRO weeds group, Assistant and Deputy Chief of CSIRO Entomology 1991-97 and Chief of the Division from 1997 to 2002.  An acknowledged francophile since his Montpellier days, Jim was also inaugural President of the ACT Chapter of the Australian French Association for Science and Technology. He was President of the Australian Entomological Society from 1997-2000 and External Advisor (Science & Research) to the Environmental Risk Management Authority, New Zealand in 2000. 

Jim retired in 2003, but has had his finger dragged back into a number of pies since then.